Abstract
This review set out to answer several questions related to tumour immunology and the gut. It is evident that in patients with gastrointestinal cancer there is a general depression of the immune response and this seems to be correlated with the stage of the disease. Paradoxically a specific immune response against definable tumour antigens can be demonstrated, both cellular and humoral mechanisms being involved although the complexities of this paradox require further analysis. Immunotherapy has been employed in gastrointestinal tumours in a sporadic way. The results suggest that gastrointestinal neoplasms may respond at least as well as other tumours. A firm conclusion awaits the results of controlled trials in which the bulk of the tumour has been effectively dealt with by other means or where combined immunochemotherapy is being used.